Ternary PtSmCo NPs electrocatalysts with enhanced oxygen reduction reaction

PtSmCo ternary metal nanoparticles (NPs) were synthesized as electrocatalysts for oxygen reduction reaction (ORR). Firstly, SmCo NPs were prepared by potentiostatic electrodeposition in ionic liquids (ILs), and the average particle diameter of SmCo NPs corresponds to about 238 nm (-0.65 V), 72 nm (-0.75 V) and 45 nm (-0.85 V), respectively. Secondly, displacement and reductions of SmCo NPs occur in the K2PtCl4 and L-ascorbic acid sodium with about 3 nm of Pt NPs which grow on the surface of SmCo NPs to form PtSmCo ternary metal NPs. Studies of cycle voltammetry (CV) and line sweep voltammetry (LSV) indicate that the electrocatalytic property for ORR generates a decreasing order of commercial Pt/ C > PtSmCo0.85 > PtSmCo0.75 > PtSmCo0.65. Accelerated durability testing (ADT) after 10000 cycles shows that PtSmCo0.85 NPs electrocatalyst decreases by similar to 40% in electrochemical active surface areas (ECSA), the half-wave potential (E-1/2) only negatively shifts by 14 mV and decreases by -13.6% in mass activity (MA). When compared with JM Pt/C, where it decreases by similar to 49% in ECSA, E-1/2 is negatively shifted by 40 mV and decreased by similar to 50% in MA. Therefore, PtSmCo0.85 NPs electrocatalyst is more stable than JM Pt/C. (C) 2020 Published by Elsevier B.V. on behalf of Chinese Society of Rare Earths.